This proposal is for the renewal of a predoctoral and postdoctoral training program in Quantitative Neuroscience at Princeton University. The way neuroscience research is carried out is rapidly changing and becoming much more dependent on, and engaged with, the physical, mathematical and information sciences. New technologies are providing data of unprecedented complexity and scale. fMRI and MEG map activated regions of the human brain with increasing resolution and temporal precision, while multi-electrode recording and optical imaging using voltage and calcium sensors provide detailed information on the spatial patterns of electrochemical activities in neural circuits and single neurons. Increasingly, the questions addressed with these technologies are systems level questions that concern the interactions of many components in networks. How sensory and motor information is represented across the activity of a population of neurons, how working memory and decisions are implemented in neural circuits, and how interacting biochemical pathways in a single synapse can coordinate plasticity and growth are all examples of contemporary network questions in neuroscience. The answers to such questions are not only of interest to basic scientists; they are also a necessary precursor to understanding disturbances of brain function in psychiatric disorders, and how these give rise to disturbances of mental function. While there has been tremendous progress in identifying disturbances of neurotransmitter function in psychiatric illness, this has not been matched by comparable progress in our understanding of how such disturbances produces disturbances of systems-level function that underlie clinical symptoms. Our training program in quantitative neuroscience addresses these changes and challenges by providing predoctoral and postdoctoral instruction and research opportunities in a combined curriculum of formal theoretical techniques and computational methods on the one hand and hands-on inquiry-based project laboratory experience on the other. This program is a cornerstone of Princeton's new Neurosciences Institute emphasizing neural coding and dynamics, bringing together faculty from Psychology, Biology, Physics, Chemistry, Engineering and other disciplines to provide a directed curriculum with cutting-edge technology for empowering future neuroscientists with quantitative methods.